CN109217346B - Back-to-back direct current power transmission system based on virtual synchronous machine and control method - Google Patents
Back-to-back direct current power transmission system based on virtual synchronous machine and control method Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/30—Reactive power compensation
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
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Abstract
The invention relates to a back-to-back direct current transmission system based on a virtual synchronous machine and a control method, wherein the system comprises two current converters which are directly connected with direct current sides, and a difference value between an acquired actual direct current voltage and a set direct current voltage instruction is adjusted by an adjuster to generate a first power difference value; the method comprises the steps of obtaining the inverse of second mechanical power which is subjected to active adjustment in a virtual synchronous machine control mode of a second converter, summing the inverse of the second mechanical power and a first power difference value to obtain first mechanical power which is subjected to active adjustment in a virtual synchronous machine control mode of a first converter, wherein the first mechanical power and the second mechanical power are used for generating the electrical angle of alternating current of the first converter and the second converter.
Description
Technical Field
The invention belongs to the field of high-voltage power transmission, and particularly relates to a back-to-back direct-current power transmission system based on a virtual synchronous machine and a control method.
Background
With the adjustment of energy structures in China and the promotion of power grid construction planning, the flexible direct current transmission system can be widely applied to the advantages of being capable of supplying power to island areas and the like by independently, flexibly and controllably using active power and reactive power without power grid commutation voltage, and is developed towards the direction of high voltage and large capacity.
At present, a Voltage Source Converter Based High Voltage Direct Current transmission system (VSC-HVDC) Based on a fully-controlled power electronic device mostly adopts conventional Direct Current control Based on PI double-loop decoupling under a synchronous rotating coordinate system, and active and reactive control targets in the control are mostly fixed numerical values, and cannot actively respond to changes of system Voltage and frequency, and cannot play a role in supporting Voltage and frequency of a High-capacity VSC on an alternating Current system. And VSC shows zero inertia characteristic, and along with VSC-HVDC's permeability in the electric wire netting constantly improves, the corresponding reduction of generator kludge capacity demand in the electric power system, electric wire netting equivalent rotary inertia reduces, leads to system frequency modulation ability to obviously weaken, is very unfavorable for electric power system safety and stability to operate. In addition, the VSC-HVDC under the conventional control mode needs to realize uninterrupted operation under an island mode and a networking mode through switching of the control mode, so that high requirements are provided for a smooth and seamless mode switching strategy of the VSC, the design difficulty of a control system is increased, electrical impact in the switching process is difficult to avoid, and the VSC-HVDC is not favorable for load safety and stability power supply.
In recent years, a VSC control technology based on a virtual synchronous generator is gradually developed in micro-grid systems, wind power generation systems and other systems, and the VSC embodies the operating characteristics of the synchronous generator by simulating the mechanical and electrical equations, frequency modulation, voltage regulation control and the like of the traditional synchronous generator, so that the voltage and the frequency of an electric power system are actively regulated, and the VSC control technology is suitable for parallel operation of a single machine and multiple machines. This is of great value for the VSC-HVDC system to solve the above problems.
A paper entitled "virtual synchronous generator technology and expedition" in volume 21 of journal of "power system automation" is introduced to a Virtual Synchronous Generator (VSG) and an operation control strategy thereof, as shown in fig. 1, the virtual synchronous generator includes a main circuit and a control system, the control system is a core for realizing the virtual synchronous generator, and mainly includes a VSG body model and a control algorithm, the control algorithm mainly simulates characteristics of active frequency modulation, reactive voltage regulation and the like of the synchronous generator from external characteristics, wherein active-frequency control regulates power by detecting a power difference Δ P to control virtual mechanical torque output, as shown in fig. 2.
However, currently, the academic community researches on the Virtual Synchronous Machine (VSM) technology only focuses on a single VSC or frequency modulation and voltage regulation control thereof. When the method is applied to a back-to-back VSC-HVDC system formed by direct connection of direct current sides without a direct current circuit, how to ensure the stability of direct current voltage of the back-to-back system, realize the frequency control of a double-end alternating current system and adapt to the island working condition of the alternating current system at any end is the primary problem faced by the popularization of the technology to the VSC-HVDC system, and deep research needs to be carried out.
Disclosure of Invention
The invention aims to provide a back-to-back direct-current power transmission system based on a virtual synchronous machine and a control method, which are used for effectively improving the frequency modulation capability of the system and ensuring the safe and stable operation of a power system under the conditions that the installed capacity requirement of a generator set is reduced and the equivalent rotating inertia of a power grid is reduced.
In order to solve the technical problem, the invention provides a back-to-back direct current power transmission system control method based on a virtual synchronous machine, which comprises the following steps:
the direct current transmission system is controlled by a virtual synchronous machine, wherein a first converter and a second converter are arranged to generate respective mechanical power and reference voltage amplitude values through respective active regulation and reactive regulation, and modulation waves for controlling the first converter and the second converter are generated through a virtual synchronous machine body algorithm;
the difference value of the collected actual direct current voltage and a set direct current voltage instruction is regulated by a regulator to generate a first power difference value; and the mechanical power of the second converter is inverted and is summed with the first power difference value to be used as the mechanical power of the first converter.
And summing the set power instruction, the second active regulating power difference value obtained according to the frequency controller of the second converter and the first active regulating power difference value obtained according to the frequency controller of the first converter to obtain the mechanical power of the second converter.
The set second frequency instruction is differed with a second actual frequency detected by a second current converter and multiplied by a second active power regulating coefficient to obtain a second active power regulating power difference value; and the set first frequency command is differed with the first actual frequency detected by the first converter and multiplied by a first active regulation coefficient to obtain the first active regulation power difference value.
Reactive power regulation of the first converter comprises the following sub-steps:
multiplying the difference between the set first reactive instruction and the first actual reactive power detected by the first converter by a first reactive regulation coefficient to obtain a first regulation difference value of the reference voltage of the first converter; the set first voltage instruction is differed from the actual alternating voltage detected by the first converter, and a second regulation difference value of the reference voltage of the first converter is obtained through regulation by a regulator;
and summing the first regulating difference value of the reference voltage of the first converter, the second regulating difference value of the reference voltage of the first converter and the set first voltage instruction to generate the reference voltage amplitude of the first converter.
Reactive power regulation of the second converter comprises the following sub-steps:
multiplying the difference between the set second reactive instruction and the second actual reactive power detected by the second converter by a second reactive power regulation coefficient to obtain a first regulation difference value of the reference voltage of the second converter; the set second voltage instruction is differed from the actual alternating voltage detected by the second converter, and a second regulating difference value of the reference voltage of the second converter is obtained through regulation by a regulator;
and summing the first adjustment difference value of the reference voltage of the second converter, the second adjustment difference value of the reference voltage of the second converter and the set second voltage instruction to generate the reference voltage amplitude of the second converter.
In order to solve the technical problem, the invention further provides a back-to-back direct current power transmission system based on the virtual synchronous machine, which comprises a first current converter and a second current converter, a first active adjusting module, a second active adjusting module and a virtual synchronous machine body algorithm module, wherein the first current converter and the second current converter are directly connected at the direct current sides;
the second active power regulating module: for generating mechanical power of the second converter;
a first active power conditioning module: the power control device is used for adjusting the difference value between the collected actual direct current voltage and a set direct current voltage instruction through the regulator to generate a first power difference value; inverting the mechanical power of the second converter, and summing the inverted mechanical power and the first power difference value to obtain the mechanical power of the first converter;
the virtual synchronous machine body algorithm module: and the AC power supply is used for respectively generating an AC current instruction and a phase angle of the first current converter and the second current converter according to the output of the first active regulating module and the second active regulating module.
The second active power regulating module is further configured to sum a set power instruction, a second active power regulating power difference value obtained according to the frequency controller of the second converter, and a first active power regulating power difference value obtained according to the frequency controller of the first converter, so as to obtain the mechanical power of the second converter.
The set second frequency instruction is differed with a second actual frequency detected by a second current converter and multiplied by a second active power regulating coefficient to obtain a second active power regulating power difference value; and the set first frequency command is differed with the first actual frequency detected by the first converter and multiplied by a first active regulation coefficient to obtain the first active regulation power difference value.
Still include the first adjusting module that does not successfully: the first reactive power regulating device is used for multiplying the difference between the set first reactive instruction and the first actual reactive power detected by the first converter by a first reactive power regulating coefficient to obtain a first regulating difference value of the reference voltage of the first converter; the set first voltage instruction is differed from the actual alternating voltage detected by the first converter, and a second regulation difference value of the reference voltage of the first converter is obtained through regulation by a regulator; and summing the first regulating difference value of the reference voltage of the first converter, the second regulating difference value of the reference voltage of the first converter and the set first voltage instruction to generate the reference voltage amplitude of the first converter.
Still include the second reactive power adjustment module: the second reactive power regulating device is used for multiplying a second reactive power command which is set and a second actual reactive power detected by the second converter by a second reactive power regulating coefficient to obtain a first regulating difference value of the reference voltage of the second converter; the set second voltage instruction is differed from the actual alternating voltage detected by the second converter, and a second regulating difference value of the reference voltage of the second converter is obtained through regulation by a regulator; and summing the first adjustment difference value of the reference voltage of the second converter, the second adjustment difference value of the reference voltage of the second converter and a set second voltage instruction to generate the reference voltage amplitude of the second converter.
The invention has the beneficial effects that: the difference value of the collected actual direct current voltage and the set direct current voltage instruction is adjusted by the adjuster to generate a first power difference value; the second mechanical power which is subjected to active regulation in the virtual synchronous machine control mode of the second converter is inverted and summed with the first power difference value to be used as the first mechanical power which is subjected to active regulation in the virtual synchronous machine control mode of the first converter; the first mechanical power and the second mechanical power are used for generating the electrical angle of the alternating current of the first converter and the second converter.
According to the invention, when the first converter performs direct-current voltage control and the second converter performs active power control and double-end alternating-current system frequency control, the two converter stations also perform reactive power regulation respectively, so that the voltage and frequency stability of the alternating-current system can be effectively improved, the running reliability of the direct-current system is ensured, meanwhile, seamless switching of networking/island working conditions can be realized without control mode regulation, and the method has good technical advancement.
Drawings
FIG. 1 is a schematic circuit diagram of a prior art virtual synchronous generator;
FIG. 2 is a schematic diagram of active-frequency control of a prior art virtual synchronous generator;
FIG. 3 is a schematic diagram of a back-to-back VSC-HVDC system virtual synchronous machine control scheme;
FIG. 4 is a detailed diagram of the virtual synchronous machine ontology algorithm module.
Detailed Description
The following further describes embodiments of the present invention with reference to the drawings.
The embodiment of the back-to-back direct current power transmission system based on the virtual synchronous machine comprises the following steps:
the VSC-HVDC system shown in FIG. 3 comprises two VSC converters1And VSC2Wherein the VSC1Being a first converter, the active regulating part of which is controlled by a direct voltage, VSC2The active regulation part of the second converter is active power control. VSC1And VSC2The control system comprises a virtual synchronous machine control part and a current control and modulation part. The virtual synchronous machine control part is composed of a first active adjusting module, a first passive adjusting module, a second active adjusting module, a second reactive adjusting module and a virtual synchronous machine body algorithm module, and the specific process of the virtual synchronous machine body algorithm is shown in fig. 4. VSCi(wherein i is 1 or 2) current instruction i output by the virtual synchronous machine body algorithm moduleabciAnd alternating current angle thetaiAs input to the subsequent stage part, and closed-loop controlled to generate VSCiI aboveabciAnd thetaiIn (1) is 1 or 2, iabc1Is firstConverter VSC1Output alternating current command, iabc2For the second converter VSC2Output alternating current command, theta1Is a first converter VSC1Phase angle of output, θ2For the second converter VSC2The phase angle of the output.
VSC1The first active power regulating module comprises a direct current voltage closed-loop control for maintaining the stability of the direct current voltage of the system, and the adopted control algorithm is as follows: the actual value U of the direct current voltagedcrefAnd the set instruction value UdcrefMaking a difference, and adjusting by a proportional integral regulator to obtain an active power adjustment quantity delta P1As the first power difference, the first power difference is compared with the VSC2Actively regulated mechanical power Pm2Is added to obtain the VSC1First mechanical power P for active regulationm1。
VSC1In the first idle adjustment module, the set first idle instruction Qref1First actual reactive power Q detected with the first converter1Differencing, multiplying by a first reactive adjustment factor kq1Obtaining the VSC1A reference voltage first regulation difference; a first voltage command U to be setacref1Actual AC voltage U detected with the first converterac1Making difference, and adjusting by a regulator AVR to obtain VSC1A reference voltage second regulation difference; VSC1First regulation difference value of reference voltage, VSC1The second regulation difference of the reference voltage and the set first voltage instruction E1Summing to generate a reference voltage amplitude E of the first converterp1。
VSC2The second active power adjusting module comprises a power setting instruction PrefAnd a frequency modulation control link, which is used for controlling the active power flow of the direct current system and simultaneously carrying out frequency support control of the double-end alternating current system, and adopts a control algorithm as follows: the first frequency command value fref1And VSC1Frequency of (f) is actually measured1Making a difference, and adjusting by a proportional controller to obtain a first active power adjustment power difference value delta P for active power adjustmentf1At the same time, VSC2Second frequency command value fref2With the actual measured value f of the frequency2Making a difference, and obtaining a second active power regulation power difference value delta P for active power regulation through the proportional controllerf2，△Pf1、△Pf2And the set active power instruction PrefAdd as VSC2Second mechanical power P for active regulationm2。
VSC2In the second reactive power regulation module, a set second reactive power instruction Qref2Second actual reactive power Q detected with the second converter2Differencing and multiplying by a second reactive power regulation coefficient kq2Obtaining the VSC2A reference voltage first regulation difference; the set second voltage instruction Uacref2Actual AC voltage U detected with the second inverterac2Making difference, and adjusting by a regulator AVR to obtain VSC2A reference voltage second regulation difference; VSC2First regulation difference value of reference voltage, VSC2The second regulation difference of the reference voltage and the set second voltage instruction E2Summing to generate a reference voltage amplitude E for the second converterp2。
Due to VSC1And VSC2And a back-to-back wiring mode is adopted, so that the frequency measurement value and the mechanical power instruction are interactively transmitted between the two devices, and the timeliness and the convenience are realized.
VSC-HVDC system double-end networking operation2Regulating active power command PrefTo change the active power flow transmission with the local end AC system, the VSC maintains the stability of the DC voltage of the system1The power needs to be adjusted synchronously, and under the control scheme of the invention patent, the active power command needing to be adjusted is added to the mechanical power command P as a feedforward termm1In the middle, therefore, the direct-current voltage closed-loop control part only needs to output small delta P1The fluctuating power in the transient state adjusting process can be compensated, and based on the scheme, the direct-current voltage stability of the system is well guaranteed, so that the operation reliability of the system is guaranteed.
In addition, if any end alternating current system generates transient power disturbanceAnd cause the frequency of the AC system to fluctuate, then VSC2The second mechanical power P can be timely adjusted according to the frequency fluctuation condition of the double-end systemm2Namely, the active power flow of the VSC-HVDC system is regulated, so that the power disturbance of the system is shared to inhibit the fluctuation of the frequency of the double-end alternating current system, and the frequency stability of the double-end alternating current system is improved.
When the alternating current system fault at any end of the back-to-back VSC-HVDC system enters an island working condition, the active output of the VSC-HVDC can be rapidly adjusted by the action of the rotary inertia in the virtual synchronous machine body algorithm of each end converter station, so that the rapid change of the system frequency is inhibited. At the same time, VSC2The frequency control in the active power regulation module and the alternating voltage control in each station reactive power regulation module can reduce the fluctuation quantity of the frequency and the voltage amplitude of an alternating current system at an island end by changing the mechanical power and the alternating voltage amplitude, thereby ensuring the stability of the alternating current system under the island working condition and realizing the smooth and seamless networking/island working condition switching. Likewise, VSC1Will still be at Pm2The direct current voltage of the system is rapidly stabilized under the feedforward action, so that the operation reliability of the system is guaranteed.
By combining the analysis, the virtual synchronous machine control scheme of the back-to-back VSC-HVDC system provided by the invention can effectively improve the voltage and frequency stability of the alternating current system, ensure the running reliability of the direct current system, realize the seamless switching of networking/island working conditions without control mode adjustment and has good technical advancement.
The invention also provides a back-to-back direct current power transmission system control method based on the virtual synchronous machine, which comprises the following steps: the direct current transmission system is controlled by a virtual synchronous machine, wherein the first current converter and the second current converter generate respective mechanical power and reference voltage amplitude values through respective active regulation and reactive regulation, and modulation waves for controlling the first current converter and the second current converter are generated through a virtual synchronous machine body algorithm; the collected actual direct current voltage is differed from a set direct current voltage command and is adjusted by an adjuster to generate a first power difference value; and the mechanical power of the second converter is inverted and is summed with the first power difference value to be used as the mechanical power of the first converter.
The above-mentioned back-to-back dc power transmission system control method is actually the control method adopted in the embodiment of the back-to-back dc power transmission system based on the virtual synchronous machine of the present invention, and the description of the control method in the above-mentioned embodiment is sufficiently clear and complete, so detailed description of the embodiment of the back-to-back converter control method is not repeated.
The above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the same, and after reading the present application, those skilled in the art will make various modifications or alterations of the present invention with reference to the above embodiments within the scope of the claims of the present patent application.
Claims (8)
1. A back-to-back direct current transmission system control method based on a virtual synchronous machine is characterized by comprising the following steps:
the direct current transmission system is controlled by a virtual synchronous machine, wherein a first converter and a second converter are arranged to generate respective mechanical power and reference voltage amplitude values through respective active regulation and reactive regulation, and modulation waves for controlling the first converter and the second converter are generated through a virtual synchronous machine body algorithm;
the difference value of the collected actual direct current voltage and a set direct current voltage instruction is regulated by a regulator to generate a first power difference value; inverting the mechanical power of the second converter, and summing the inverted mechanical power and the first power difference value to obtain the mechanical power of the first converter;
and summing the set power instruction, the second active regulating power difference value obtained according to the frequency controller of the second converter and the first active regulating power difference value obtained according to the frequency controller of the first converter to obtain the mechanical power of the second converter.
2. The virtual synchronous machine-based back-to-back direct current transmission system control method according to claim 1, wherein a set second frequency command is subtracted from a second actual frequency detected by a second converter and multiplied by a second active regulation coefficient to obtain a second active regulation power difference value; and the set first frequency command is differed with the first actual frequency detected by the first converter and multiplied by a first active regulation coefficient to obtain the first active regulation power difference value.
3. The virtual synchronous machine based back-to-back direct current transmission system control method according to any one of claims 1-2, wherein the reactive power regulation of the first converter comprises the sub-steps of:
multiplying the difference between the set first reactive instruction and the first actual reactive power detected by the first converter by a first reactive regulation coefficient to obtain a first regulation difference value of the reference voltage of the first converter; the set first voltage instruction is differed from the actual alternating voltage detected by the first converter, and a second regulation difference value of the reference voltage of the first converter is obtained through regulation by a regulator;
and summing the first regulating difference value of the reference voltage of the first converter, the second regulating difference value of the reference voltage of the first converter and the set first voltage instruction to generate the reference voltage amplitude of the first converter.
4. The virtual synchronous machine based back-to-back direct current transmission system control method according to any one of claims 1-2, wherein the reactive power regulation of the second converter comprises the sub-steps of:
multiplying the difference between the set second reactive instruction and the second actual reactive power detected by the second converter by a second reactive power regulation coefficient to obtain a first regulation difference value of the reference voltage of the second converter; the set second voltage instruction is differed from the actual alternating voltage detected by the second converter, and a second regulating difference value of the reference voltage of the second converter is obtained through regulation by a regulator;
and summing the first adjustment difference value of the reference voltage of the second converter, the second adjustment difference value of the reference voltage of the second converter and the set second voltage instruction to generate the reference voltage amplitude of the second converter.
5. A back-to-back direct current transmission system based on a virtual synchronous machine comprises a first current converter and a second current converter which are directly connected at the direct current sides, and is characterized by further comprising a first active adjusting module, a second active adjusting module and a virtual synchronous machine body algorithm module;
the second active power regulating module: for generating mechanical power of the second converter;
a first active power conditioning module: the power control device is used for adjusting the difference value between the collected actual direct current voltage and a set direct current voltage instruction through the regulator to generate a first power difference value; inverting the mechanical power of the second converter, and summing the inverted mechanical power and the first power difference value to obtain the mechanical power of the first converter;
the virtual synchronous machine body algorithm module: the first active regulation module is used for generating an alternating current instruction and a phase angle of the first current converter and the second current converter respectively according to the output of the first active regulation module and the output of the second active regulation module;
the second active power regulating module is further configured to sum a set power instruction, a second active power regulating power difference value obtained according to the frequency controller of the second converter, and a first active power regulating power difference value obtained according to the frequency controller of the first converter, so as to obtain the mechanical power of the second converter.
6. The back-to-back direct current transmission system based on the virtual synchronous machine according to claim 5, wherein the set second frequency command is subtracted from a second actual frequency detected by a second converter and multiplied by a second active regulation coefficient to obtain a second active regulation power difference value; and the set first frequency command is differed with the first actual frequency detected by the first converter and multiplied by a first active regulation coefficient to obtain the first active regulation power difference value.
7. The virtual synchronous machine-based back-to-back direct current power transmission system according to any one of claims 5 to 6, further comprising a first reactive power adjusting module: the first reactive power regulating device is used for multiplying the difference between the set first reactive instruction and the first actual reactive power detected by the first converter by a first reactive power regulating coefficient to obtain a first regulating difference value of the reference voltage of the first converter; the set first voltage instruction is differed from the actual alternating voltage detected by the first converter, and a second regulation difference value of the reference voltage of the first converter is obtained through regulation by a regulator; and summing the first regulating difference value of the reference voltage of the first converter, the second regulating difference value of the reference voltage of the first converter and the set first voltage instruction to generate the reference voltage amplitude of the first converter.
8. The virtual synchronous machine-based back-to-back direct current transmission system according to any one of claims 5 to 6, further comprising a second reactive power adjusting module: the second reactive power regulating device is used for multiplying a second reactive power command which is set and a second actual reactive power detected by the second converter by a second reactive power regulating coefficient to obtain a first regulating difference value of the reference voltage of the second converter; the set second voltage instruction is differed from the actual alternating voltage detected by the second converter, and a second regulating difference value of the reference voltage of the second converter is obtained through regulation by a regulator; and summing the first adjustment difference value of the reference voltage of the second converter, the second adjustment difference value of the reference voltage of the second converter and a set second voltage instruction to generate the reference voltage amplitude of the second converter.
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| CN110571849B (en) * | 2019-08-20 | 2020-12-29 | 南京国电南自电网自动化有限公司 | Rapid control method for responding to power instruction by virtual synchronous machine |
| CN110896226B (en) * | 2019-11-29 | 2023-03-14 | 国网江苏省电力有限公司常州供电分公司 | Improved direct power control method of flexible direct current transmission system |
| EP4136729B1 (en) | 2020-04-17 | 2024-04-10 | Hitachi Energy Ltd | Multi-port grid forming control for grid interties |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104953686A (en) * | 2014-03-24 | 2015-09-30 | 国家电网公司 | Control method for charge-discharge virtual synchronization motor for electromobile energy storage |
| CN106849140A (en) * | 2016-10-28 | 2017-06-13 | 许继集团有限公司 | A kind of virtual synchronous machine control method of Large Copacity energy storage, apparatus and system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9893524B2 (en) * | 2012-12-20 | 2018-02-13 | Abb Schweiz Ag | Coordinated control method of generator and SVC for improving power throughput and controller thereof |
-
2017
- 2017-07-06 CN CN201710547610.7A patent/CN109217346B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104953686A (en) * | 2014-03-24 | 2015-09-30 | 国家电网公司 | Control method for charge-discharge virtual synchronization motor for electromobile energy storage |
| CN106849140A (en) * | 2016-10-28 | 2017-06-13 | 许继集团有限公司 | A kind of virtual synchronous machine control method of Large Copacity energy storage, apparatus and system |
Non-Patent Citations (1)
| Title |
|---|
| 基于虚拟同步电机技术的VSC-HVDC整流侧建模及参数设计;高丙团等;《中国电机工程学报》;20170120;第37卷(第2期);第534-543页 * |
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